A5101809472- Orbital Angular Momentum in Optics
- Photoacoustic and Ultrasonic Imaging
- Gold and Silver Nanoparticles Synthesis and Applications
- Orthopaedic implants and arthroplasty
- Optical Coherence Tomography Applications
- Engineering Applied Research
- Digital Holography and Microscopy
- Thermography and Photoacoustic Techniques
- Knee injuries and reconstruction techniques
- Advanced Fluorescence Microscopy Techniques
- Nanoplatforms for cancer theranostics
- Near-Field Optical Microscopy
- Optical Coatings and Gratings
- Total Knee Arthroplasty Outcomes
- Refrigeration and Air Conditioning Technologies
- Photonic Crystals and Applications
- Bone and Joint Diseases
- Radio Astronomy Observations and Technology
- Adaptive optics and wavefront sensing
- Laser Material Processing Techniques
- Surface Roughness and Optical Measurements
- ZnO doping and properties
- Transition Metal Oxide Nanomaterials
- Optical measurement and interference techniques
- Advanced optical system design
Korea Basic Science Institute
2015-2024
Chonnam National University
2011-2013
Purdue University West Lafayette
1994-1998
In laser-plasma interactions (LPI), the laser beam mode is a critical parameter when trying to explore new physical phenomena. Of various spatial modes, Laguerre-Gaussian (LG) with vortex phase has attracted considerable attention due its unique features, including ability carry an orbital angular momentum. Due this, it been actively applied LPI, which mainly utilize ultrashort intense pulses. However, existing transmissive phase-manipulating optical elements have several limitations in LPI...
Abstract Hydrogels are widely used as scaffold materials for constructing in vitro three-dimensional microphysiological systems. However, their high sensitivity to various external cues hinders the development of hydrogel-laden, microscale, and high-throughput chips. Here, we have developed a long-term storable gel-laden chip composite built multi-well plate, which enables situ cell encapsulation facilitates analysis. Through optimized chemical crosslinking freeze-drying method (C/FD),...
Plasmonic photothermal therapy (PPTT) using gold nanoparticles (AuNPs) has shown great potential for use in selective tumor treatment, because the AuNPs can generate destructive heat preferentially upon irradiation. However, PPTT not been added to practice, owing insufficient heating methods and tissue temperature measurement techniques, leading unreliable inaccurate treatments. Because properties of vary with laser power, particle optical density, depth, accurate prediction generation is...
Wavelength-tunable spiral-phase-contrast (SPC) imaging was experimentally accomplished in the visible wavelengths spanning a broad bandwidth of ∼200 nm based on single off-axis spiral phase mirror (OSPM). By rotation an OSPM, which designed with integer orbital angular momentum (OAM) l = 1 at wavelength 561 and incidence angle 45°, high-quality SPC obtained different wavelengths. For comparison wavelength-tunable using plate (manufactured to generate OAM nm) performed three (473, 561, 660...
We report parallel spectral-domain optical coherence tomography (OCT) at 500 000 A-scan/s. This is the highest-speed (SD) OCT system using a single line camera. Spectrally encoded line-field scanning proposed to increase imaging speed in SD-OCT effectively, and tradeoff between speed, depth range, sensitivity demonstrated. show that three modes of 125k, 250k, 500k A-scan/s can be simply switched according sample imaged considering range sensitivity. To demonstrate biological performance...
Abstract The plasmonic photothermal (PPT) characteristics of gold nanostructures have been extensively investigated theoretically and experimentally due to their potential for use materials science industry. management the size shape nanoparticles has a key issue in development better solutions PPT heat generation because determine resultant properties. However, light absorption is mainly dependent on wavelength orientation incident light; hence, maintaining uniform critical achieving...
Wavelength-tunable optical vortices with a topological charge equal to <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mi>l</mml:mi> <mml:mo>=</mml:mo> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mn>1</mml:mn> </mml:mrow> </mml:math> of orbital angular momentum (OAM) were experimentally realized using single off-axis spiral phase mirror (OSPM) lasers various visible-light wavelengths. Using an OSPM designed for 561 nm and incidence angle 45°, circular...
In this study, a portable and large-area blackbody system was developed following series of processes including design, computational analysis, fabrication, experimental analysis evaluation. The designed to be lightweight (5 kg), its temperature could exceed the ambient by up 15 °C under operation. A carbon-fiber-based heat source used achieve uniform distribution. shield fabricated from an insulation material embedded at opposite side heating element minimize loss. prototype based on design...
With an increase in the size and shape complexity of optical surfaces, periodic structure on surface can have significant effects beam profile, which propagates system. This necessitates a quantitative analysis interference between diffracted modes formed propagating profile after reflection surfaces with structures. Herein, generalized equation, determines period constructive by Bragg scattering, is presented for only two given mth nth order. Two theoretical calculations, one being...
Abstract Photothermal imaging is useful for detecting individual nanoparticles and obtaining the absorption spectra. This study presents a wide-field photothermal reflectance spectroscopy technique achieved by incorporating pump beam, probe charge-coupled device (CCD) camera into commercial microscopic setup. The presented design does not require precise alignment between beams enables observation of numerous during image acquisition. Despite use simple processing method, i.e., four-bucket...
Spiral-phase-contrast imaging, which utilizes a spiral phase optical element, has proven to be effective in enhancing various aspects of such as edge contrast and shadow imaging. Typically, the implementation spiral-phase-contrast imaging requires formation Fourier plane through 4f configuration addition an existing microscope. In this study, we present what believe novel single spiral-phase-objective, integrating plate, can easily simply applied standard microscope, conventional objective....
The periodic structure on the optical surface affects beam shape and its propagation. As size of elements becomes larger complicated, quantitative analysis effect indispensable given that it is very difficult to completely eliminate microscopic structures. Herein, we have experimentally investigated Bragg scattering from an with extremely small aspect ratios (~10-5) groove densities (0.5 lines/mm). We observed period constructive interference formed due propagation 0th, 1st, -1st modes...
Download This Paper Open PDF in Browser Add to My Library Share: Permalink Using these links will ensure access this page indefinitely Copy URL Generation of Wavelength- and Orbital Angular Momentum-Tunable Extreme-Ultraviolet Vortex Beams a Spiral Phase Mirror 32 Pages Posted: 22 Feb 2024 See all articles by Sunwoo LeeSunwoo LeeKorea Basic Science InstituteDong Uk KimKorea InstituteJi Yong BaeKorea InstituteIlkyu HanKorea InstituteSangwon HyunKorea InstituteHwan HurKorea InstituteKye-Sung...
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In this paper, we propose a sensitivity-enhanced thermoreflectance microscopy (TRM) system employing an electronic auto-balancing photoreceiver for effective thermal fault localization through Si substrate. The proposed in the auto-balanced detection not only improves signal-to-noise ratio (SNR) by approximately five times compared to that achievable via normal but also mitigates inherent noise, such as pseudothermoreflectance signals, using optical zooming. Moreover, temperature variations...
To evaluate the pre-stress in menisci of a human knee joint, technique microindentation was adopted. Five specimens each for lateral and medial attached to tibia were prepared from joints Korean cadavers represent state meniscus. create test stress-free meniscus, meniscus resected cut into three parts, which subsequently metal plate. Indentations carried out both state. The pre-stresses evaluated using load-versus-depth curves. Compressive found menisci. For indentation region, higher than...
Spectrally encoded confocal microscopy (SECM) is a high-speed reflectance technique. Here, we present method to integrate optical coherence tomography (OCT) and SECM for complementary imaging by adding orthogonal scanning the configuration. The co-registration of OCT automatic, as all system components are shared in same order, eliminating need additional alignment. proposed multimode compact cost-effective while providing benefits aiming guidance. Furthermore, speckle noise can be...
Abstract Biochip-based research is currently evolving into a three-dimensional and large-scale basis similar to the in vivo microenvironment. For long-term live high-resolution imaging these specimens, nonlinear microscopy capable of label-free multiscale becoming increasingly important. Combination with non-destructive contrast will be useful for effectively locating regions interest (ROI) large specimens consequently minimizing photodamage. In this study, photothermal optical coherence...